/**
 * Shared formatting helpers for channel monitor views (admin + user).
 *
 * Centralises:
 *  - status / provider label + badge class lookups
 *  - latency / availability / percent number formatting
 *
 * i18n keys live under `monitorCommon.*` so admin and user views share the
 * same translation source.
 */

import { useI18n } from 'vue-i18n'
import type { MonitorStatus, Provider } from '@/api/admin/channelMonitor'
import {
  PROVIDER_OPENAI,
  PROVIDER_ANTHROPIC,
  PROVIDER_GEMINI,
  STATUS_OPERATIONAL,
  STATUS_DEGRADED,
  STATUS_FAILED,
  STATUS_ERROR,
} from '@/constants/channelMonitor'

const NEUTRAL_BADGE = 'bg-gray-100 text-gray-800 dark:bg-dark-700 dark:text-gray-300'

export interface AvailabilityRow {
  primary_status: MonitorStatus | ''
  availability_7d: number | null | undefined
}

export function useChannelMonitorFormat() {
  const { t } = useI18n()

  function statusLabel(s: MonitorStatus | ''): string {
    if (!s) return t('monitorCommon.status.unknown')
    return t(`monitorCommon.status.${s}`)
  }

  function statusBadgeClass(s: MonitorStatus | ''): string {
    switch (s) {
      case STATUS_OPERATIONAL:
        return 'bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-300'
      case STATUS_DEGRADED:
        return 'bg-yellow-100 text-yellow-800 dark:bg-yellow-900/30 dark:text-yellow-300'
      case STATUS_FAILED:
        return 'bg-red-100 text-red-800 dark:bg-red-900/30 dark:text-red-300'
      case STATUS_ERROR:
      default:
        return NEUTRAL_BADGE
    }
  }

  function providerLabel(p: Provider | string): string {
    if (p === PROVIDER_OPENAI || p === PROVIDER_ANTHROPIC || p === PROVIDER_GEMINI) {
      return t(`monitorCommon.providers.${p}`)
    }
    return p || '-'
  }

  function providerBadgeClass(p: Provider | string): string {
    switch (p) {
      case PROVIDER_OPENAI:
        return 'bg-green-100 text-green-800 dark:bg-green-900/30 dark:text-green-300'
      case PROVIDER_ANTHROPIC:
        return 'bg-orange-100 text-orange-800 dark:bg-orange-900/30 dark:text-orange-300'
      case PROVIDER_GEMINI:
        return 'bg-blue-100 text-blue-800 dark:bg-blue-900/30 dark:text-blue-300'
      default:
        return NEUTRAL_BADGE
    }
  }

  function formatLatency(ms: number | null | undefined): string {
    if (ms == null) return t('monitorCommon.latencyEmpty')
    return String(Math.round(ms))
  }

  function formatPercent(v: number | null | undefined): string {
    if (v == null || Number.isNaN(v)) return '-'
    return `${v.toFixed(2)}%`
  }

  function formatAvailability(row: AvailabilityRow): string {
    if (!row.primary_status) return '-'
    return formatPercent(row.availability_7d)
  }

  return {
    statusLabel,
    statusBadgeClass,
    providerLabel,
    providerBadgeClass,
    formatLatency,
    formatPercent,
    formatAvailability,
  }
}